Air conditioners are devices for cooling or warming indoor spaces such as homes, restaurants, or offices. In order to efficiently cool or warm an indoor space divided into a plurality of rooms, multi-air conditioners capable of cooling or warming a plurality of rooms have been developed. A multi-air conditioner includes a plurality of indoor units which are all connected to one outdoor unit and are installed in different rooms. Then, each of the indoor units may be driven in either a heating mode or a cooling mode so that an air conditioning function can be provided.
A typical air conditioner is generally divided into an indoor unit having a heat exchanger and an outdoor unit having a compressor and a heat exchanger and is driven by controlling the supply of power and a coolant to the compressor or the heat exchangers.
However, in the case of conventional air conditioners, a plurality of power modules of a control unit for controlling an outdoor fan and a compressor or a heat exchanger in an indoor unit are designed as linear transformers, and thus, the interconnection between the power modules is very complicated. Accordingly, the reliability of the control unit may considerably deteriorate, additional cost for handling electromagnetic interference (EMI) may be incurred, and it may become difficult to alter control variables.